In addition to RC5, also exclude MDC2 from compilation unless
the algorithm is explicitly requested.

Configure

diff --git a/Configure b/Configure
index bd9d4a6..3c9f96d 100755
--- a/Configure
+++ b/Configure
@@ -153,7 +153,7 @@
 "debug-ben-debug",	"gcc:-DBN_DEBUG -DREF_CHECK -DCONF_DEBUG -DBN_CTX_DEBUG -DCRYPTO_MDEBUG -DPEDANTIC -DDEBUG_SAFESTACK -g3 -O2 -pedantic -Wall -Wshadow -Werror -pipe::(unknown)::::::",
 "debug-ben-strict",	"gcc:-DBN_DEBUG -DREF_CHECK -DCONF_DEBUG -DBN_CTX_DEBUG -DCRYPTO_MDEBUG -DCONST_STRICT -O2 -Wall -Wshadow -Werror -Wpointer-arith -Wcast-qual -Wwrite-strings -pipe::(unknown)::::::",
 "debug-rse","cc:-DTERMIOS -DL_ENDIAN -pipe -O -g -ggdb3 -Wall::(unknown):::BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${x86_elf_asm}",
-"debug-bodo",	"gcc:-DL_ENDIAN -DBN_DEBUG -DREF_CHECK -DCONF_DEBUG -DBN_CTX_DEBUG -DBIO_PAIR_DEBUG -DPEDANTIC -g -march=i486 -pedantic -Wshadow -Wall::-D_REENTRANT:::BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${x86_elf_asm}",
+"debug-bodo",	"gcc:-DL_ENDIAN -DBN_DEBUG -DREF_CHECK -DCONF_DEBUG -DBIO_PAIR_DEBUG -DPEDANTIC -g -march=i486 -pedantic -Wshadow -Wall::-D_REENTRANT:::BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${x86_elf_asm}",
 "debug-ulf", "gcc:-DTERMIOS -DL_ENDIAN -march=i486 -Wall -DBN_DEBUG -DBN_DEBUG_RAND -DREF_CHECK -DCONF_DEBUG -DBN_CTX_DEBUG -DCRYPTO_MDEBUG -DOPENSSL_NO_ASM -g -Wformat -Wshadow -Wmissing-prototypes -Wmissing-declarations:::CYGWIN32:::${no_asm}:win32:cygwin-shared:::.dll",
 "debug-steve",	"gcc:-DL_ENDIAN -DREF_CHECK -DCONF_DEBUG -DDEBUG_SAFESTACK -DCRYPTO_MDEBUG_ALL -DPEDANTIC -g -mcpu=i486 -pedantic -Wno-long-long -Wall -Werror -Wshadow -pipe::-D_REENTRANT::-rdynamic -ldl:BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${x86_elf_asm}:dlfcn:linux-shared",
 "debug-steve-linux-pseudo64",	"gcc:-DL_ENDIAN -DREF_CHECK -DCONF_DEBUG -DBN_CTX_DEBUG -DDEBUG_SAFESTACK -DCRYPTO_MDEBUG_ALL -DOPENSSL_NO_ASM -g -mcpu=i486 -Wall -Werror -Wshadow -pipe::-D_REENTRANT::-rdynamic -ldl:SIXTY_FOUR_BIT:${no_asm}:dlfcn:linux-shared",
@@ -600,6 +600,7 @@
 # All of the following is disabled by default (RC5 was enabled before 0.9.8):
 
 my %disabled = ( # "what"         => "comment"
+                 "mdc2"           => "default",
                  "rc5"            => "default",
                  "shared"         => "default",
                  "zlib"           => "default",